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authorJean Delvare <jdelvare@suse.de>2024-04-30 19:29:32 +0300
committerJean Delvare <jdelvare@suse.de>2024-04-30 19:29:32 +0300
commit0ef11f604503b1862a21597436283f158114d77e (patch)
treeddc51254ea3979b08bb67a3662c4e353f2628011 /drivers/firmware
parentcf770af5645a41a753c55a053fa1237105b0964a (diff)
downloadlinux-0ef11f604503b1862a21597436283f158114d77e.tar.xz
firmware: dmi: Stop decoding on broken entry
If a DMI table entry is shorter than 4 bytes, it is invalid. Due to how DMI table parsing works, it is impossible to safely recover from such an error, so we have to stop decoding the table. Signed-off-by: Jean Delvare <jdelvare@suse.de> Link: https://lore.kernel.org/linux-kernel/Zh2K3-HLXOesT_vZ@liuwe-devbox-debian-v2/T/ Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Diffstat (limited to 'drivers/firmware')
-rw-r--r--drivers/firmware/dmi_scan.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index 015c95a825d3..ac2a5d2d4746 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -102,6 +102,17 @@ static void dmi_decode_table(u8 *buf,
const struct dmi_header *dm = (const struct dmi_header *)data;
/*
+ * If a short entry is found (less than 4 bytes), not only it
+ * is invalid, but we cannot reliably locate the next entry.
+ */
+ if (dm->length < sizeof(struct dmi_header)) {
+ pr_warn(FW_BUG
+ "Corrupted DMI table, offset %zd (only %d entries processed)\n",
+ data - buf, i);
+ break;
+ }
+
+ /*
* We want to know the total length (formatted area and
* strings) before decoding to make sure we won't run off the
* table in dmi_decode or dmi_string